Insulating material and method of making the same



March 21, 1933.

c. A. UPSON INSULATING MATERIAL AND METHOD OF MAKING THE SAME Filed March 28, 1950 2 Sheets-Sheet l 11v VENTOR aarks zfqason,

March 21, 19.33.

C. A. UPSON INSULATING MATERIAL AND METHOD OF MAKING .THE SAME Filed March 28, 1930 2 Sheets-Sheet 2 INVENTORY 'fz'sA TTORNE V Patented Mar. 21, 1933 UNITED sTATEs PATENT OFFICE CHARLES A. UPSON, OI LOCKPORT, NEW YORK, ASSIGNOB TO THE (IRON COMPANY, 01'

LOOKPORT, NEW YORK, A CORPORATION 01 NEW YORK INSULATING MATERIAL AND METHOD 0], MAKING THE SAME Application filed March 28, 1980. Serial N0. 439,793.

The present invention relates to insulating material which may be used, for example, for insulating the walls of buildings against the passage of heat therethrough, and to a method of making such insulating material. An object of the invention is the provision of a generally improved, more economical, and more satisfactory material of this nature, and of a simple, efiicient, economical, and satisfactory method of making such material.

Another object of the invention is the provision of an insulating material which is fire resistant to an unusually high degree, and which will retain its fire resistant qualities permanently instead of becoming less fire resistant and more inflammable as time goes on, as is often the case with insulating material of previously known kinds.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Fig. 1 is a cross section taken transversely through a piece of insulating material constructed in accordance with a preferred embodiment of the invention:

Fig. 2 is a fragmentary cross sectionon a larger scale, illustrating details not readily apparent in Fig. 1;

Fig. 3 is a diagrammatic horizontal section through a portion of a wall of a building, illustrating the preferred form of insulating material applied to the wall;

Fig. 4 is a view similar to Fig. 1 showing a modified form of construction;

Fig. 5 is a view similar to Fig. 2 showing details of the modified form illustrated in Fig. 4;

Fig. 6 is a fragmentary cross section through a piece of insulating material showing an alternative form ofliner;

Fig. 7 is a similar view illustrating another form of liner;

Fig. 8 is a similar view illustrating still another form of liner;

- Fig. 9 is a fragmentary cross section through a piece of insulating material illustrating a modified form of edge reenforcement, and

Fig. 10 is a similar view showing still another possible form of edge reenforcement.

Similar reference numerals throughout the several views indicate the same parts.

The present invention provides an insulat ing material especially suitable for use in the walls of buildings or other structures in order to insulate the walls against passage of heat therethrough. The insulating material com prises in general a layer of fibrous material constituting a filling between layers of sheet material which form what might be termed liners for the filling. The filling constitutes the main heat insulating element, while the liners serve to hold the filling in place and preferably to keep moisture from the filling. The insulating material is ordinarily put up in the form of relatively long strips of the proper width to extend between adjacent studs of a wall, as illustrated in Fig. 3, and the carpenter or other person applying the material cuts the long strips into appropriate lengths to reach from the floor to the ceiling; for example. The long strips are swatched or folded back and forth like accordion pleats, to make a compact package for shipment.

- The filling is indicated by the numeral 20 in all of the figures of the drawings. It is composed of a' occulent mass of loosel associated and interlaced fibres and pre erably the fibres are treated so as to render them fire-resistant to a high degree, or what is usually'known'as' fireproof, or the fibres themselves may be more or less noninflammable.

Various kinds of fibres might be employed but it is preferred at present to use jute fibres for this filling material. Such fibres may be obtained economically, especially when pur chased in the form of old gunny-sacks, or the like. Jute fibres in their normal or untreated state are exceedingly inflammable and are thus unsuitable for use as insulation in the walls of buildings, because of the great fire hazard occasioned by such use. Heretofore it has been. pro osed to fireproof jute or other fibres by sprin ling fireproofing salts in the fibrous bat. This is not wholly successful, however, since the degree of fire-resistance obtained by the salts is relatively low, and

. silicate, but this is not satisfactory for sevj ectionable.

eral reasons. Sodium silicate. is apt to seep through and discolor the liners, which is obply coats them. .In time, due to the moisture To this end, the

m the air and the caustic inthe silicate, it disintegrates or becomes a powder and falls off of the fibres so that the fire-resisting effect is lost or gradually reduced. Also, the silicate renders the fibres brittle, causing them to break easily into very much smaller fibres with reduced insulating qualities.

Thus the prior methods of fireproofing the filling of insulating material of this character have usually been unsatisfactory in various ways. As distinguished from them, the present invention contemplates the provision of a satisfactory fireproof filling in which the fire-resisting qualities are permanent and do not lessen with the passage of time, and in which the fire-resistance is unusually high.

resent invention contemplates that the brous material shall be treated with a fireproofing liquid, which will actually impregnate the fibres, rather than merely coat them- The treating liquid, for

example, may be ammonium sulphate, or an equivalent chemical, and other chemicals may be added to render the material objectionable to vermin or rodents. The treatment of the fibres may be accomplished either by immersing them in a bath of the fireproofing chemical, or by subjecting the fibres to a spray of the fireproofing chemical. Such treatment, whether it be a bath or a spray, may be accomplished either before or after the fibres are formed into the hat of interlaced fibres or filling for the insulating material, but it is found to be more satisfactory to fireproof the fibres before they are made up or formed into the filling.

When the fibrous material for the filling is obtained in the form of gunny-sacks, pieces of cloth, or the like, it is preferred to subject the fibres to the fireproofing chemical while the fibres are still in this original form, the fireproofing treatment being preceded only by a washing and drying operation, if such is needed.

The gunny-sacks, pieces of cloth, or "other textile fabric after being fireproofed and dried are disintegrated and the fibres are then picked by any suitable picking element, such as a Garnett picker. The picked fibres are then formed into a loose or flocculent mass of loosely associated fibres for use as the fill- Furthermore, the sodium silicate does not impregnate the fibres, but siming material, by the aid of condenser or suction rolls or any other suitable forming apparatus. One of the important advantages of fireproofing the fibres while they are still in the form of a textile fabric and before they are picked is that the factory can be kept substantially free from untreated fibres which would be highly inflammable, and thus the fire hazard in the factory. is very mate rially reduced.

When the fibrous material is fireproofed substantially as soon as it is received at the factory and'in the same form in which it is received, as contemplated by the present invention, it will be seen that there will be no danger of combustion of the material as it passes through the disintegrating or picking elements or forming rolls, and any piles of fibres which accumulate on the floor, as they usually do in. factories making products of this kind, will be non-inflammable to such a degree that a burning match may be dropped upon a pile without danger, whereas such action would be disastrous if the fibres had not been previously fireproofed.

If the fibrous material-arrives at the factory not in the form of a textile fabric but in the form of bales or sheets of jute fibres, it is preferred to subject it to the fireproofing treatment substantially immediately and before the fibres are picked, in order to have little or no inflammable fibrous material on hand. a

After the fibrous filling has been formed by suction rolls or the like into a'bat of interlaced fibres, liners of sheet material are applied to the opposite sides thereof, so as to envelop the fibrous filling to hold it in place,

and preferably also to exclude moisture subcated generally by the numeral 21 in Figs. 1, 3, 4, 9, and 10. Heretofore it has been proposed to make the liners of plain untreated paper, but this has the disadvantage that the paper liners are inflammable and-may burn readily even though the fibrous-filling has been fireproofed or rendered fire-resistant, as described above. The present invention contemplates that the liners as well as the fibrous filling shall be fire-resistant to a high degree and preferably also water-resistant in order that the liners may serve to keep substantial amounts of moisture from the filling.

The preferred form of liners is illustrated particularly in 2, and comprises two layers 22 and 23 of cellulosic material such as kraft paper which may be inherently inflammable but which is treated to render-it fire-resistant, and a layer 24 of waterproofing material preferably to serve also as anadhesive to hold the layers-22 and 23 together, with the result that the three layers form aunitary liner sheet. The adhesive 24 may be asphaltum, for example, or any suitproof adhesive, which forms 'a layer sub stantially impervious to water.

Heretofore it has been difiicult if not imssible as a practicable matter to make insu- Biting material of this eneral nature both fireproof and waterproo One of the dlfiiculties has been thatmost waterproofing materials, such as asphaltum, varnishes, lacquers, etc,, are exceeding] inflammable, and in order to reduce the in ammability of the insulating material it has been necessary to omit the desirable waterproofing feature. At other times, attempts have been made to fireproof a layer of asphaltum or the llke by the use of materials such as silicate of soda, but such an arrangement is not wholly successful because the silicate at times discolors the liner sheets in an objectionable manner and renders them brittle, and it also disintegrates 1n the course of time so that the fire-resistance gradually becomes less and less.-

According to the present invention, however, the above mentioned disadvantages are overcome and an exceedingly satisfactory liner which is both fireproof and Waterproof is provided. Althoug the layer of asphaltum 24, or other waterproof adhesive, may be exceedingly inflammable by itself, it is found that when it is placed between two sheets which have been fireproofed, the resulting composite sheet will not burn readily. In .other words, the inflammability of the waterproofing agent is smothered between the two fireproofed sheets.

As a further measure of protection, it may be desired to reduce the inflammability of the asphaltum or other waterproofing agent, which may be done by adding to the asphaltum unslaked lime, ammonium hosphate, ammonium chloride, or the like. ome of the above mentioned chemicals are suitable for use with one kind or grade of asphaltum and other chemicals are most suitable for use with other kinds or grades of asphaltum. The particular chemical to be used will depend, of course, on the grade or kind of asphaltum used.

The addition of the chemical may not render the asphatum entirely fireproof .by it self, but it will greatly reduce the inflammability of the asphaltum so that the fire-resistance of the composite liner sheet when the asphaltum has been treated in this way is somewhat higher than the fire-resistance of such a sheet in which untreated asphaltum is used. The treatment of the asphaltum,although desirable and preferable, is not absolutely essential, however, since it is found that plain untreated asphaltum between sheets of fire-1e sistant material results in a composite liner sheet which has a ver high degree of fire-resistance which is su cient for all ordinary purposes. Such a composite sheet will not burn when held in an open flame such as that .85 of a match;

proofed by the use of a special fireproofing formula having a reaction which is close to the iso-electric point of cellulose and having a surface tension which is relatively low so that the fireproofing liquid will enter the sheet readily. p.

Preferably the fireproofing solution is a plied to the liners after they have been ma e u in composite form with the waterproofing a hesive. In: other words, the composite sheet comprising the layers 22, 23, and 24 is run through a bath or otherwise subjected to the action of the fireproofing liquid. This results 'not only in impregnating the cellu-' losic sheets 22 and 23, but also each tiny particle of asphaltum or other "adhesive which may seep into the sheets 22 and 23 becomes coated or impregnated with the fireproofing agent, whichwould not be done if the sheets 22 and 23 were fireproofed se arately before being joined together to ma e up the composite liner.

The natural color of the kraft paper ordinarily used for the layers 22 and 23 is brown or yellowish. If other materials are used in place of kraft paper, the natural colors maybe difi'erent, but the natural colors of all of the material ordinarily used are usually fairly light and not at all black in color. It is desirable, however, to havev the outer surface of the liner sheets colored black, partly so that the material will not become easily soiled during handling or trans portation, and partly because the public is accustomed to associatin the color black with waterproofed buildmg products, and the fact that this insulating material is waterproofed or water-resistant may be emphasized considerably by having the exposed surfacepf the liners of black color.

The present invention accordingly contemplates that the outer surface of each liner shall be colored black, although the inner surface of the liner may be left in its natural color if desired. In case the liner is made up of a composite structure having two or more sheets of paper or the like, the desired color of the outer-surface may be obtained easily and satisfactorily by using a black sheet as the outer layer of the composite sheet. As

a convenient way of obtaining the desired 7 color, it is contemplated that black coloring matter shall be put in the fireproofing bath into a composite sheet, the use of black coloring in the fireproofing bath will obviously result in coloring both sides of the liner, but color upon the inner surface is not objectionable although it is not necessary. In case the separate sheets 22 and 23o the liner are fireproofed before being made up into the composite liner sheet, as may be preferred in some instances, then it is contemplated that the black coloring matter shall be added to the firepro-ofing bath through which the outer sheet 23 is passed, but not to the bath through which the inner sheet 22 is passed. Hence after the two sheets are made up into the composite liner with the waterproofing layer 24 between them, the outer sheet 23 will be black and will give the desired black appearance to the insulating material, but the inner sheet will remain of its natural color or of such color as may be imparted toit by the fireproofing solution.

The liners are preferably secured to the fibrous filling 21 by means of adhesive. Heretofore, ininsulating materials of this general character, it has been customary to apply a continuous layer of adhesive to the inner face of the liner, but according to the present invention the adhesive is applied in a discontinuous layer such as strips or dots of adhesive. Such strips or dots are shown in cross section at 25 in Fig. 2. It is found that the use of such discontinuous adhesive joins the liners satisfactorily to the filling and at the same time results in a product which is much more flexible than is the case when a continuous layer of adhesive is used. Flexibility of the insulating material is an important feature, since it permits the material to be bent easily so that it may be applied in any position desired to unusual or peculi'ar structures. The dots or strips of adhesive may be applied to the liners by means of suitably formed brushes or rolls during the manufacture of the insulating material or bat and preferably just before the liners are applied to the filling.

Longitudinal extending strips or tapes 26 of paper or the like are preferably placed along the edges of the filling of the bat on both sides thereof, before the liners are applied, and preferably the strips of each pair are stitched to each other through the filling 20 by stitching 27, shown diagrammatically in Fig. 2. The stitching operation is preferably done after the tapes 26 are applied to the filling 20 but before the liners are applied so that the stitches pass through the tapes but not through the subsequently applied liners, thus leaving the liners imperforate. Adhesive is applied between the tapes 26 and the liners, so that the liners are firmly affixed to the tapes. The adhesive between the liners and tapes will serve also to hold the stitches 27 in place and to prevent them from unraveling in case one or more stitches should break. Preferably also adhesive is applied to the inner surface of each tape 26 so that the tape is firmly cemented to the fibrous filling as well as being sewed thereto.

The adhesive used for joining the tapes to.

the filling and for joining the liners to the tapes and to the filling may be of any suitable kind. It may be of either vegetable, animal,

or mineral origin, or a mixture of two or more kinds of adhesive. It is important to use an adhesive which is permanent and which will not deteriorate in time, and also one which will not react in any undesirable way with any of the chemicals or substances which are used for fireproofin the filler or the liners or for waterproofing t e liners, and which will not spot or discolor the liners.

Both longitudinal edges of the insulating material are preferably substantially thinner than the main' or central portion of the ma-,, terial, so that the edges or marginal portions 'filed February 8, 1930, for machine for mak-' ing insulating bats. When the forming rolls are lagged in the manner described in said application, the fibrous filling which issues from the forming rolls is of substantially uniform thickness throughout, but at the point Where lagging has been applied to the condenser rolls (which point corresponds to the edges of the bats in the present instance) the filling contains substantially less fibres per unit of surface area than at other oints where the rolls have not been lagged. ubsequently the application of the strips or tapes 26 and the action of the sewing machine in sewing them together, with or without the'supplemental action of compression rollers at the edges of the bat, compresses the marginal portion of the filling. Because the filling in the compressed marginal portion contains relatively few fibres per unit of area and is relatively loose and fluffy, it does not expand again to its original size after it has been compressed, and the edge of the bat accordingly remains thin, substantially as is illustrated in Figs. 1 and 2. 1

An insulating material constructed as detion of the material is bent at an angle'to the central portion and is applied to the side of one of the studs. Although the insulating material may be ap lied in other ways, this is the usual and preibrable method of applyingit. The thin edges or mar al portions of the insulating material of ti d present invention are of considerable importance, since they allow the edges to be bent in the desired manner easily and quickly so that the insulating bats may be installed with a minimum of time and trouble. If the edges of the bat are of the same thickness which is desirable at the center, there is great difliculty in bendin an edge to apply it properly to the stud, an the liners are veryapt to pull loose from the filling during the attempt at bending. All this is obviated by the use of the thin marginal portions of the present invention.

In order to assist the insulating material still further to bend in the desired manner at its ed s, the present invention contemplates that t e material or the liners on each side thereof shall be crinkled in a longitudinal direction adjacent the edges. The term crinkle as used in this specification and in the accompanying claims is intended in a broad generic sense and includes scoring, corrugatmg or otherwise ofperating upon the liners to make them more exible and pliable.

In Figs. 1 to 3 inclusive, crinkling is shown at 35, and is illustrated for the sake of clearness as relatively large corrugations on a somewhat exaggerated scale. The crinkling actually used might be aslarge as that illustrated if desired, but it is preferred in most instances to use somewhat smaller corrugations or score marks. Preferably the crinkling is slightly inwardly of the extreme edge ofthe insulating material'so that the crinkled portion may act as a hinge to permit easy bending of the portion between the crinkling and the extreme edge relative to other portions of the material.

When the marginal portion of the bat is crinkled in this manner, the flexibility in-. herent in the thin edge is still further increased so that the marginal portion may be ling of the central portion of the bat than Another feature of the present invention consists of the rovision of a re'enforcing strip extending ongitudinall along the insulating bat at or close to eac edge thereof. Such a strip is shown at 40 in Figs. 1 to 3, and is referably applied on the outside surface 0 one of the liners, bein held in place by adhesive and/or by stitchmg. This reenforcing strip 40 is preferably of heavy cardboard or the like, and is designed to obviate the necessity of using lath-or similar strips which have heretofore been employed when applying the insulating material to the studding.

As shown in Fig. 3, the nails 41 which secure the material to the studding are driven through the reenforcing strips 40, the insulating material being applied in such position that-these strips are on the inside of the hat. The reenforced edge provided by these strips prevents the bat from tearing away from the nails, and the strips act as a bridge between the nails, which are ordinarily spaced about eight to twelve inches apart, so that the portions of the bat between adjacent nails are held firmly against the studs. When reenforcing strips such as this are not used, it is found that the insulating material is apt to buckle or bulge away from the studs between the nails unless the nails are spaced close to each other or unless strips of separate material'such as lath are employed in the posi is forced to come at or inwardly from the inner edge of the strip 40, as shown in Fig. 3.

The, insulating material, .as above mentioned, is preferably put up in the form of bundles in which a long strip of material is swatched or folded back and forth at intervals, somewhat like accordion pleats. The reenforcin strips 40 may be cut or scored at appropriate intervals corresponding to the points at which the insulating material is folded in the package in which it is put up, so that the reenforcement will not interfere with such folding.

Although it is preferable for the crinkling 35 to be along a zone spaced somewhat inwardly from the edge of the bat, yet if desired this crinkling may extend all the way to the edge of the bat, so that it covers all or the larger part of the thin edge portion. Such crinkling, extending from the edge of the bat inwardly for' a substantial distance is illustrated at 45 in Figs. 4 and 5.

This form of crinkling illustrated inFigs.

4 and 5 may be used without any reenforcing strip, or a reenforcing strip may alsobe employed if desired. For example, as shown in these views, a reenforcing strip 46 of heavy fabric such as canvas or duck or the like, may be used and this fabric also may be crinkled in a tranverse direction to correspond to the crinkling of the liners. The fabric strip 46 may be and preferably is stiffened, as by the use of sizing or the like. V

A fabric strip of this kind prevents the nails from tearing out of the bat when the bat is nailed to studding as shown in Fig. 3. In many instances the fabric reenforcement strips will be found to be suflicientl'y strong and rigid so that no lath is needed, but at other times it may be desirable to secure the insulating material to the studding by nailing through lath or similar strips laid on top of fabric strips 46.

The fabric reenforcement 46 may be used with crinkling in the position shown in Fig. 2, or it, like the previously described reenforcement 40, may be used without any crinkling whatever if preferred.

The reenforcing strips may also be applied to the insulating material in other positions instead of being secured to the outside surface thereof, as in Figs. 2 and 5. For example, as shown in Fig. 9, a reenforcing strip 50 may be placed between the liners and in contact with one of the paper strips 26, being secured thereto by adhesive or stitching. If desired, nail holes 51 may be punched through the reenforcing strip 50 and the liner a-t appropriate intervals, say eight to twelve inches apart. Such nail holes may be used if desired also with other forms of reenforcingstrips, such as those shown in Figs. 2, 5. and 10. The reenforcing strip' 50 may be of heavy cardboard or the like, similar to the strip 40 previously described.

In Fig. 10 there is illustratedstill another possible position of the reenforcing strip. Here the strip 55 is placed between the liners but out of contact with either of them, being interposed in the fibrous filling with some filling on each side of the reenforcing strip.

Stitches 51 extending through the reenforcing strip and the liners hold the former in position and prevent lateral displacement thereof.

Although it is preferred to use a liner of the kind illustrated in Fig. 3. and described in connection therewith, yet other forms of liners may also be employed if desirable under any special circumstances. For example, the layers 22 and 23 of the liner may be composed of cloth or other fabric rather than of paper, if an unusually strong liner is needed for any reason, and the term cellulosic material used in the claims is intended to cover textile fabrics or the like as well as paper, as bestos paper, or similar materials. One of the layers 22 and 23 may be of fabric and the other of paper, if desired. Irrespective of what material is used, the liners are preferably fireproofed or rendered fire-resistant to a very high degree in the manner above described.

Instead of using only two layers of cellulosic material held together by a waterproof adhesive, three or more layers may be usedif paper, or all three may be of cloth, or part of them may be of paper and the rest of cloth. Furthermore, the central layer 62 may be of asbestos, while the layers and 61 of paper'or cloth serve to strengthen the ashestos sheet which is relatively weak by itself.

In Fig. 7 there is illustrated still another form of liner, comprising a single layer of fireproofed cellulosic material 65 having an external coating 66 of waterproofing material. This waterproofing material may be asphaltum, which will thus give the desired black outer surface to the insulating material without the necessity of coloring the cellulosic material itself. It is often preferred, however, to use a relatively thin layer of paraflin for the coating 66. This is advantageous because a thin layer of paraflin is transparent,

'While a layer of asphaltum is not, and when paraffin is used, a trade mark or directions for use may be printed upon the cellulosic material 65 and may still be read easily even after the coating 66 is applied. Slow burning wax, such as Halowax, may alsobe used satisfactorilyin a manner similar to parafiin.

The preferred method of making the form of product illustrated in Fig. 7 is to take a sheet of thoroughly fireproofed paper which has been colored black preferably in the fireproofing solution, run such fireproofed black.

sheet through a printing press to print a trade mark and/or directions for use on the sheet in ink of a color such as'blue which will contrast with the black surface of the sheet, and then apply a relatively thin coating of paraffin to the printed surface of the sheet. Preferably the parafiin is chilled immediately after application, to produce a thin, even coating which does not seep excessively into the sheet. The printed and coated sheet is then applied to the fireproofed bat-filling 20 and aflixed thereto by discontinuous adhesive such as the dots or strips 25. The printed side of the sheet is outwardly, of course, so that the printed matter may be read easily through the transparent coating of parafiin,

product.

In Fig. 8 there is shown a liner comprising a sheet of asbestos and a sheet 71 ofcellu losic material such as kraft paper, althou h cloth may be used if desired. The sheets %0 and 71 are affixed to each other by a waterproofin strengt ens the asbestos sheet 70 which is relatively weak; The strengthening sheet is preferably fireproofed as has been described above in connection with the other forms of liners.

In order to make the asbestos sheet 70 stronger, the asbestos fibres may be mixed with wood pulp or other fibres of the kind used in paper making, before being formed into the sheet. Furthermore, the pulp fibres may be fireproofed in some permanent manner as has been described above, before being mixed with the asbestos fibres, or the entire sheet may be subjected to the fireproofing liquid after it is formed. In some instances; a satisfactory liner may be formed of a single sheet of asbestos, thus strengthened by the addition of the other fibres, and fireproofed, and a layer of asphaltum or other waterproofing material may be placed onone side of the sheet.

Whenever cloth is used for one or all of the layers of a liner, the cloth is fireproofed in the same manner previously described. Irrespective of the particular kind or form of liner employed, it is preferably thoroughly and permanently fireproofed or rendered fire-resistant to an exceedingly high degree, and the fibrous filling between the layers is preferably likewise fireproofed or rendered fire-resistant'to an exceedingly high degree, so that the resulting composite insulating material will not support combustions and will not burn even when an open flame is applied to the liners or to the filling or both.

It will be seen that an exceedingly satisfactory insulating material has been devised, which may be easily applied to walls or the like, which is of relatively permanent character, and which will not increase the fire hazard in a building in which it is used, but on the contrary will tend to decrease the fire hazard by forming "a fireproof layer in the walls which will impede the progress of flames through the walls.

While certain embodiments of the invention have been disclosed, it is to be understood that the inventive idea may be carried out in a. number of ways. This application is therefore not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the spirit of the invention or the scope of the appended claims.

I claim as myinvention: 1. Flexible heat insulating material for walls, comprising a filling of loosely associadhesive, so that' the sheet 71 ated fibrous material and a liner on each side of said filling of fibrous material each of said liners comprising a pluralityof layers of cellulosic material held together by a layer of as haltum chemically treated to reduce the in ammability of said asphaltum.

2. Flexible heat insulatin material for ated Jute bres. c emically treated to render them fire resistant, and a liner on each side of said jute filling, each of said liners comprisin a lurality of layers of cellulosic material e1 together by a layer of asphaltum chemicall treated to reduce the inflammability of sai asphaltum.

; 3. An insulatin walls having stud mg, said bat comprisin a filling of loosely associated fibres having along each of two opposite edges a marginal portionvcontaining less fibres per unit of area ortion of said bat extends between the studing.

4. An insulatin walls having stud ing, said bat comprising a filling of loosely associated fibres and a liner of sheet material on each side of said filling, said bat having an afiixing portion of less thickness than the main central portion of the bat, the filling in said affixing portion having less fibres or unit of area than in the main portion 0 the bat, so that said afiixing portion may be attached conveniently to studortion of said bat exdin while the main ten s between the stu din 5. An insulatin bat for application to walls having stud ing, said bat comprising a bat for application to- .walls com risin a filling o loosely associbat for application to.

filling of loosely associated fibres and a liner of sheet material on each side of said filling,

said bat having along each of two opposite edges an afiixing portion of less thickness throughout a substantial width than the thickness of the main central portion of the bat, the filling in said alfixing portions having 2 less fibres per unit of area than in the main portion of the bat, so that each of said aflixmg portions may be bent easily at an angle to the main portion of the bat for attachment to studding while the main portion of the bat extends between the studding.

6. An insulating bat for application to Walls having studding, said bat comprising a filling of loosely associated fire resistant fibres and a fire resistant liner on each side of said filling, said bat having along each of two opposite edges an affixing portion of less thickness throughouta substantial width than thethickness of the main central portion of the bat, the filling in said alfixing poreach side of said filling, said bat having along each of two opposite edges an aiiixingJ portion of less thickness throughout a su stantial width than the thickness of the main central portion of the bat, the filling in said affixing portions having less fibres per unit of area than in the main portion of the bat, so that each of said afiixing portions may be bent easily at an angle to the main portion of. the bat for attachment to studdin while the main portion of the bat extends between the studdmg.

8. An insulating bat for application to walls having studding, said bat comprising a fillin of loosely associated fibres and a liner inclu ing a plurality of sheets of fire resistant cellulosic material held together by a water resistant adhesive on each side of said filling, said bat having along each of two opposite edges an afiixing portion of less thickness throughout a substantial width than the thickness of the main central portion of the bat, the filling in said aifixing portions having less fibres per unit of area than in the main portion of the bat, so that each of said afiixing portions may be bent easily at an an gle to the main portion of the bat for attachment to studding while the main portion of the bat extends between the studding.

9. An insulating bat for application to walls having studding, said bat comprising a filling of loosely associated fibres having along each of two opposite edgesa marginal portion containing less fibres per unit of area than the main portion of said filling, a pair of strips of sheet material extending along each of said marginal portions on opposite sides thereof, stitching extending through the strips of each pair and through the interposed filling, and a liner of sheet material on each side of said filling and overlying said strips, to provide a bat having relatively thin marginal portions which may be bent easily at an angle to the main portion of the batfor attachment to studding while the main portion extendsbetween the studding.

10. An insulating bat comprising a filling of loosely associated fibrous material and a liner of sheet material on each side of said filling, said bat having a marginal portion along one edge of substantial width and of substantially less thickness than the main centralportion of the bat, so that said marginal portion may be bent easily relative to the main portion, said marginal portion being crinkled in order further to assist bending thereof.

11. An insulating bat comprising a filling of loosely associated fibrous material and a liner of sheet material on each side of said filling, said bat having a marginal portion along one edge of substantial width and of substantially less thickness than the main central portion of the bat, so that said marginal portion may be bent easily relative to the main portion, said marginal portion being crinkled along a line near the inner edge of the marginal portion in order further to assist bending thereof.

12. An insulating bat comprising a filling of loosely associated fibrous material, a liner of flexible sheet material on each side of said filling, and a strip of relatively strong reinforcing material extending along an edge of said bat, so that said bat may be held securely in place by nails driven through said reinforcing strip.

13. An insulating bat comprising a filling of loosely associated fibrous material, a liner of flexible sheet material on each side of said filling, and a strip of relatively strong and rigid reinforcing material extending along an edge of said bat, so that said reinforcing strip may be bent as a unit relative to the main portion of the bat, and so that said bat may be held securely in place by nails driven through said reinforcing strip.

14. An insulating batcomprising a filling of loosely associated fibres having a marginal portion of substantially less thickness than and containing less fibres per unit of area than the central portion of said filling, a liner of sheet material on each side of said filling, and a strip of relatively strong reinforcing material extending along an edge of said bat adjacent said marginal portion of said filling.

15. An insulating bat comprising a filling of loosely associated fibres having a marginal portion of substantially less thickness than and containing less fibres per unit of area than the central portion of said filling, a liner of sheet material on each side of said filling, and a strip of relatively strong and rigid reinforcing material extending along an edge of said bat adjacent said marginal portion of said filling and secured thereto, so that said reinforcing strip and a part of said marginal portion may be bent as a unit relative to the central portion.

16. An insulating bat comprising a filling of loosely associated fibres having a marginal portion of substantially less thickness than and containing less fibres per unit of area than the central portion of said filling, a liner of sheet material on each side of said filling, and a strip of relatively strong and rigid reinforcing material extending along an edge of said bat adjacent said marginal portion of said filling and secured thereto, so that said reinforcing strip and a part of said marginal portion may be bent as a unit relative to the central portion, said liners being crinkled along a line inwardly of said reinforcing strip in order to assist the bending of said strip relative to the central portion.

17. An insulating bat comprising a filling of loosely associated jute fibres chemically treated to render them fire resistant and a liner of fire resistant cellulosic material on each side of said filling, one of said liners being crinkled along a llne spaced slightly inwardly from and substantially'parallel to one of its edges, so that the marginal portion of the bat between said crinkled line and the adjacent edge of the bat may be bent easily at an angle to other portions of the bat.

18. An insulating bat comprising a filling of loosely associated fibres and a liner on each side of said filling, each of said liners comprising a plurality of layers of sheet'material adhesively secured to each other, said filling having a marginal portion of substanthe filling, forming grating the treated fabric and picking the fibres, forming the picked fibres into a bat filling, and applying a liner to said bat fillmg.

22. The method of making an insulating bat which comprises sub'ecting jute fibres to the action of a fireproofing liquid, picking the treated fibres, forming the picked fibres into a bat filling having less fibres per unit of area along certain marginal portions of said filling than at the main central portion of a liner comprising a'plu rality of layers of re resistant cellulosic material secured to each other by asphaltum, applying such liner to each side of said bat filling, and crinkling each of said liners adjacent said marginal portion of the bat filling to assist the bending of the marginal portion of the assembled bat relative to the main portion thereof.

CHARLES A. UPSON.

tial width and of less thickness than the main 7 portion of said filling, said liners being crinkled adjacent said marginal portion so that part of said marginal portion may be bent easily at an angle to the main portion of the bat.

19. An insulating bat comprising a filling of loosely associated jute fibres chemically treated to render them fire resistant and a liner on each side of said filling, each of said liners comprising a plurality of layers of fire resistant cellulosic material secured to each other by a layer of waterproofing adhesive, said filling having a marginal ortion of substantial width and of substantially less thickness than the main portion of said filling, said liners being crinkled adjacent said marginal portion so that part of said marginal portion may be bent easily at an angle to the main portion of the bat.

20. An insulating bat comprising a filling of loosely associated jute fibres chemically treated to render them fire resistant and a liner on each side of said filling, each of said liners comprising a plurality of layers of fire resistant cellulosic material secured to each other by a layer of waterproofing adhesive, said filling having a marginal portion of substantial width and of substantially less thickness than the main portion of said filling,

said liners being crinkled adjacent said marginal portion so that part of said marginal portion may be bent easily at an angle to the main portion of the bat, and a relatively strong reinforcing strip attached to said, I

margmal portion so that said bat may be held securely in place by nails passing through said strip.

21. The method of making an insulating bat which comprises subjecting jute fibres substantially in the form! of a textile fabric to the action of a fireproofing liquid, disinte- 

